1. 5 Minute Class Starter Write this in your notes Describe the motion of a falling object. Does it have a constant speed? Does it have a constant acceleration?

2. Physics 11 Unit 1 Lesson 20 Star International Academy Mr. David Anderson

3. Today’s Agenda 1.Class Starter 2.Free Fall – free body diagram 3.Free Fall – mathematical formulas

4. 2. Free Fall – Free Body Diagram

5. Free Body Force Diagram What is a free body force diagram? - A free body force diagram is a picture or a model showing the different forces acting on an object

6. Example: Pushing on a crate

7. Draw three free body diagrams Beginning of fall Middle of fall End of fall (no bounce)

8. Draw two free body diagrams Sheet of paper Balled up paper Falling

9. Summary  Conclusion:  What forces are acting on a falling object?  Is a falling object accelerating? How do you know this?

10. PAUSE

11. Class Starter Review the project description. - Write down at least one question that you have about it.

12. 3. Free Fall – Mathematical Model

13. Review of motion formulas  Velocity (speed) = change in position / change in time  a = d / t  Acceleration = change in velocity / change in time  a = v / t

14. Motion formula: constant speed What is the acceleration? a = 0 What is the velocity? v = v 0 (v 0 = constant or initial velocity) What is the position? x = x 0 + v 0 t initial position initial position position change due to velocity Bonus for Calculus students: Start with the formula for position: x = x 0 + v 0 t Differentiate implicitly with respect to time twice. Can you derive the other formulas?

15. Motion formula: constant acceleration What is the acceleration? a = a (a = constant acceleration) What is the velocity? v = v 0 + at What is the position? x = x 0 + v 0 t + ½at 2 initial position initial position position change due to velocity Bonus for Calculus students: Start with the formula for position: x = x 0 + v 0 t + ½at 2 Differentiate implicitly with respect to time twice. Can you derive the other formulas? position change due to acceleration

16. Constant Acceleration Formula x = x 0 + v 0 t + ½at 2 In math terms, what is the order of this formula? If you graphed this formula, what is the shape of the graph? Does this match your idea of free fall? How does the formula change if the acceleration is zero?

17. Application to Projectile Motion

18. Projectile Motion Projectile motion is a combination of motion types. How does a projectile move in the horizontal (X) direction? How does a projectile move in the vertical (Y) direction?